This invention relates to a food product, and more particularly to a dry yogurt product, and a process for preparing same. The dry product of this invention may be reconstituted to form either a liquid or a semi-solid food by the addition of a liquid such as milk.
Yogurt is a form of fermented milk which has been curdled to a smooth, creamy, or custard-like consistency. Natural yogurt is produced by the fermentation of acid-producing organisms, typically bacilli, such as Lactobacillus bulgaricus, Lactobacillus acidophilus, and Streptococcus thermophilus, as well as newly used bifidobacterium; dairy products may also include added protein, such as bovine lactoferrin. Generally, one or more such microorganisms are added to milk and then incubated until the desired amount of fermentation has occurred. The fermentation process lowers the pH of the milk and causes it to curdle. The product thus produced is ordinarily chilled to stop the intended microbial action and to inhibit undesirable microbial action, thereby preserving the product in the desired condition. It is in this form, chilled and hydrated, that yogurt is commonly sold.
A process for preparing a liquid yogurt which may be frozen is disclosed in U.S. Pat. No. 4,110,476. However, it is convenient to have an instant yogurt which may be preserved for long periods of time, and which may be reconstituted easily by the average consumer. U.S. Pat. No. 1,269,769 refers to instant yogurt drink formulations that are reconstituted with milk. Similarly, U.S. Pat. No. 4,289,788 refers to instant yogurt meal (i.e. semisolid) compositions that are reconstituted with milk. U.S. Pat. No. 4,624,853 discloses another type of instant yogurt-like product.
The texture of a yogurt is an important factor effecting its acceptability to consumers. Yogurt should be free of lumps or curds, and should exhibit a smooth, custard-like consistency. A high quality yogurt has a good texture, is low in fat, includes effective amounts of active culture, and provides a high nutritional value by way of protein, calcium, and other useful nutrients.
High quality hydrated yogurt products are sold commercially. It is also possible for consumers to produce high quality yogurt at home, although this requires a fair amount of time, effort, and skill. However, all hydrated yogurt products have a quite limited shelf life, even while refrigerated. Therefore, yogurt must be consumed soon after production to avoid spoilage, including transport of the product, even while continuously refrigerated.
An instant yogurt product would provide the benefits of both long shelf life and convenient preparation and storage. It has not been possible to produce an instant high quality yogurt product which can be conveniently reconstituted into either a yogurt drink or a yogurt meal.